The present disclosure relates generally to nano-scale surface scanning technology and, more specifically, to the manipulation of nano-scale objects by gyration.
Typical prior art scanning probe microscopes employ a probe tip sharpened to an apex of atomic scale dimensions. In general, operation of a scanning probe microscope includes bringing the probe tip into close proximity with a surface being sampled, such that a sensing device coupled to the probe tip detects local interaction between the probe tip and the sample surface. A feedback loop is often employed to maintain constant interaction strength between the probe tip and the sample surface as the probe tip scans across the sample surface. The displacement of the probe tip as it scans across the undulations of the sample surface is then detected and converted into a contour map of the surface.
This concept is generally employed by a variety of conventional scanning probe devices to investigate surface features of micro-scale and nano-scale samples. For example, scanning tunneling microscopes may be employed to detect localized interactions attributable to electronic tunneling. Atomic force microscopes may also be employed to detect localized interactions attributable to Van der Waals and atomic repulsive forces. Such arrangements can be employed to detect surfaces variations with atomic scale resolution. Other devices that operate according to this general concept include near-field scanning optical microscopes, scanning tunneling optical microscopes, near-field scanning acoustical microscopes, scanning capacitance microscopes and scanning electrochemistry microscope.
These devices may also be employed in the manipulation of nano-scale objects, such as by methods taking advantage of the repulsive forces (e.g., Pauli repulsion) between molecules. Such conventional methods, often referred to as pushing, manipulation or nano-manipulation, have been applied to many different nano-scale objects, including atoms, molecules, colloids and clusters. For example, a conventional pushing method includes selecting a molecule to be repositioned across a substrate, selecting a target location on the substrate, configuring a scanning probe device for a straight line scan from the molecule location to the target location and performing the single straight line scan, thereby xe2x80x9cpushingxe2x80x9d the molecule along a straight line to the target location.
However, successfully performing such nano-manipulation requires repulsive forces between the probe tip and the molecule being repositioned to be large enough to overcome attractive forces between the nano-scale object and the underlying substrate that can bind the nano-scale object to its current location. Accordingly, many nano-manipulation methods adjust the set-point of the feedback loop or other operating parameters during the manipulation, such as to decrease the separation between the probe tip and the surface on which the nano-scale object being repositioned is located. However, such methods have proven to be unreliable and imprecise. For example, atomic and molecular processes such as diffusion and thermally-activated hopping can lead to an intrinsic motion of the nano-scale object that compromises the intended nano-manipulation.
Accordingly, what is needed in the art is a nano-manipulation method that addresses the problems discussed above.
The present disclosure provides a method of nano-manipulation that, in one embodiment, includes providing a nano-scale object movably located over a substrate and positioning a probe of a scanning probe microscope proximate the nano-scale object. The probe is then moved across the substrate along a gyrating path proximate the nano-scale object to reposition the nano-scale object.
In another embodiment, a method of nano-manipulation according to aspects of the present disclosure includes providing a plurality of nano-scale objects movably located over a substrate and positioning a probe of a scanning probe microscope proximate the plurality of nano-scale objects. The probe is then moved across the substrate along a gyrating path proximate the plurality of nano-scale objects to reposition at least one of the plurality of nano-scale objects.
The present disclosure also introduces a system for nano-manipulation. In one embodiment, the system includes means for supporting a substrate having a nano-scale object movably located thereon, means for positioning a probe of a scanning probe microscope proximate the nano-scale object, and means for moving the probe relative to the substrate along a gyrating path proximate the nano-scale object to reposition the nano-scale object.
The foregoing has outlined preferred and alternative features of several embodiments so that those skilled in the art may better understand the detailed description that follows. Additional features will be described below that further form the subject of the claims herein. Those skilled in the art should appreciate that they can readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure.